My parents came to this country before I was born. My Father made a strict rule, GERMAN and Home and English everywhere else.
And think for a second about my Mother as she is FROM England, but Fathers edict stood.
Now this did not mean he didn't think of himself as an American, Hell the first thing he did once he got his citizenship in 1972 was enlist in the United States Marine Corps.
But my Mother embraced it whole heartily, They live in Hafia, Israel now and I don't think I have spoken to her in English in at least 2 years. Its always German or now Hebrew, I am convinced that it won't be long before she forgets English entirely.
You have to keep in practice or you forget, my dad only spoke a very few words of Italian which is why he probably went to the Pacific instead of Germany during WW2.